This is just a shambles:
A key factor that the industry has been keen to not draw too much attention to for over a year is the number of 4G & 5G devices that would no longer work, or would only work on some networks, including for Emergency Calling.
The idea that a 4G or 5G phone could somehow be affected by the shutting down of older technologies like 2G & 3G is a completely foreign concept to people, and rightfully so.
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Unlike with 2G & 3G, 4G & 5G are Data only standards and have no built-in calling functionality, let alone one as well standardised as the traditional Circuited Switched calling from 2G & 3G (GSM/UMTS).
This becomes a problem as to enable calling over 4G & 5G, devices need to have explicit software/firmware support, especially so for Emergency Calling.
Calling on 4G Networks is enabled through the use of VoLTE (Voice over LTE aka ‘4G Calling’), which is a software/firmware VoIP (Voice over Internet Protocol) calling solution for mobile phones.
The world has used VoIP Calling for decades but introducing VoIP data based calling into the mobile sector has proven very difficult.
Voice Over LTE (4G Calling) devices have been around since as early as 2013, however over years the industry has failed to ensure interoperability.